Search results for " Biosynthesis"

Identification of the reaction products of (2'-5')oligoadenylate synthetase in the marine sponge.

1998

Previously we reported on the presence of a high (2'-5')oligoadenylate synthetase activity in the marine sponge Geodia cydonium [Kuusksalu, A., Pihlak, A., Muller, W. E. G. & Kelve, M. (1995) Eur. J. Biochem. 232, 351-357]. The presence of (2'-5')oligoadenylates [(2'-5')A] in crude sponge extract was shown by radioimmunoassay and by their HPLC comigration with authentic (2'-5')A oligomers. In addition, the sponge (2'-5')oligoadenylates displayed biological activity, as determined by inhibition studies of protein biosynthesis in rabbit reticulocyte lysate. In the present study individual (2'-5')oligoadenylates synthesized by sponge enzyme were separated by HPLC. The exact composition of ever…

Acid tolerance inLeuconostoc oenos. Isolation and characterization of an acid-resistant mutant

1996

The acid tolerance ofLeuconostoc oenos was examined in cells surviving at pH 2.6, which is lower than the acid limit of growth (about pH 3.0). Acid-adapted cells survived better than non-adapted cells. Tolerance to acid stress was found to be dependent upon the adaptive pH. Acid resistance was increased by an order of magnitude for cultures adapted to a pH of about 2.9. Inhibiting protein synthesis with chloramphenicol prior to acid shock revealed that acid adaptation may involve two separate systems, one of which appears to be independent of protein synthesis. The acid-resistant mutant LoV8413, isolated during a long-term survival screen at pH 2.6, was found to be able to grow in acidic me…

Plasma membrane transporters for arginine

2004

The supply of arginine may become rate limiting for enzymatic reactions that use this semiessential amino acid as a substrate (e.g., nitric oxide, agmatine, creatine, and urea synthesis), particularly under conditions of high demand such as growth, sepsis, or wound healing. In addition, arginine acts as a signaling molecule that regulates essential cellular functions such as protein synthesis, apoptosis, and growth. In the past decade, a number of carrier proteins for amino acids have been identified on the molecular level. They belong to different gene families, exhibit overlapping but distinctive substrate specificities, and can further be distinguished by their requirement for the cotran…

Prebiotic polypeptides and the origin of biological information.

1983

Recent data on the origin of biological information are reviewed. These data corroborate the view that polyamino acids were the first informational polymers. The source of information is seen in the chemical reactivity of amino acids, their prebiotic abundance and the prebiotic environment. Evidence is presented in favor of Matsuno's protohypercycle that may have preceded Eigen's hypercycle, but that involves a translation of information from polypeptides into that of polynucleotides.

Erratum to “3D-Structure and function of strictosidine synthase – The key enzyme of monoterpenoid indole alkaloid biosynthesis” [Plant Physiol. Bioch…

2008

Herbicidally Active Derivatives of Aminomethylenebis-Phosphonic Acid-Mode of Action and Structure - Activity Relationship

1996

Abstract: (N-pyridylamino)methylenebisphosphonates exhibit strong herbicidal activity which may be reversed by supplementation of the growth media with aromatic amino acids. They appeare to be the inhibitors of aromatic amino acids biosynthesis acting as inhibitors of DAHP synthase the first enzyme of shikimate pathway. Over 40 analogues of these acids were synthesized in order to determine the structure-activity relationship.

Determination of the stability of protein pools from the cell wall of fungi.

2002

Stability of the protein populations present in the cell wall of three ascomycetous fungi Candida albicans, Saccharomyces cerevisiae and Yarrowia lipolytica was investigated. Cell wall proteins were either labeled with biotin or radiolabeled with amino acids, and chased for a period of time representing several generations. Proteins linked by non-covalent or covalent bonds were separated and their turnover was analyzed. No significant turnover took place during the chase period, and in fact radioactive proteins were accumulated in the wall during the period possibly by transfer through the secretory pathway. This transfer did not involve de novo protein synthesis; it was inhibited by azide,…

Measurement of Protein Synthesis: In Vitro Comparison of 68Ga-DOTA-Puromycin, [3H]Tyrosine, and 2-Fluoro-[3H]tyrosine

2012

Aim: Puromycin has played an important role in our understanding of the eukaryotic ribosome and protein synthesis. It has been known for more than 40 years that this antibiotic is a universal protein synthesis inhibitor that acts as a structural analog of an aminoacyl-transfer RNA (aa-tRNA) in eukaryotic ribosomes. Due to the role of enzymes and their synthesis in situations of need (DNA damage, e.g., after chemo- or radiation therapy), determination of protein synthesis is important for control of antitumor therapy, to enhance long-term survival of tumor patients, and to minimize side-effects of therapy. Multiple attempts to reach this goal have been made through the last decades, mostly u…

Carnitine transport in volume-overloaded rat hearts

1995

Carnitine concentration in tissue is generally related to mitochondrial volume-density and ability to oxidize fatty acids. The highest tissue carnitine has been detected in ventricular myocardium which, compared to other tissues, presents elevated rates of oxidative phosphorylation [1]. The ability of cardiac mitochondria to oxidize long chain fatty acids is also much higher when compared to skeletal muscle or liver sarcosomes (Table 1). Paradoxically enough, it has been known for many years [3–5] that the heart is missing γ-butyrobetaine hydroxylase [6, 7], the last enzyme of carnitine synthesizing pathway, and that in the myocardium of different species including man, the carnitine synthe…

Über die mikrobiologische Umwandlung N-haltiger Substrate. 3. Mitt.: Über die Konstitutionsaufklärung von Umwandlungsprodukten des 5-Hydroxyindols du…

1968

In Schuttelkulturen von Cordyceps militaris entstehen aus 5-Hydroxyindol zwei neue Substanzen, die nach Chromatographie an Polyamidsaulen und nachfolgender Isolierung auf Grund ihres chemischen Verhaltens gegenuber Diazomethan sowie ihrer Elementaranalysen, IR-, Massen-und NMR-Spektren als ω-N-Acetyl-5-hydroxy-tryptophan und ω-N-Acetyl-serotonin identifiziert wurden. Two new substances are produced in submerged cultures of Cordyceps militaris fed with 5-hydroxyindole. These substances, separated by column chromatography with polyamide and isolated afterwards, have been identified as ω-N-acetyl-5-hydroxytryptophan and ω-N-acetyl-serotonin by their reaction with diazomethane, by elementary an…